title: Hyperfiltration evaluated by glomerular filtration rate at diagnosis in children with cancer.
abstract: BACKGROUND
  Renal glomerular filtration rate (GFR) of pediatric cancer patients at diagnosis has previously been investigated in a limited number of studies.
  
  
  METHODS
  GFR, measured by iohexol clearance, was prospectively investigated in 55 children over the age of 1 year with malignancies, (group A). Elevated GFR (>175 ml/min/1.73 m(2)) at diagnosis was found. To investigate if this finding was consistent, a second group of 76 children with malignancies was studied, (group B). As a method control for GFR obtained by iohexol clearance, group A and B together were compared to 298 pediatric patients without cancer, group C.
  
  
  RESULTS
  GFR was elevated in 40/131 (31%) in Group A + B but only in 17/298 (6%) in Group C. GFR was significantly higher in children aged 1-5 in group A + B (47%) compared to group C (3%). Bone marrow involvement was significantly associated with higher GFR. Children without bone marrow involvement also hyperfiltrated more often than controls, but less often. Urea in urine was used as a marker of renal protein clearance in 14 patients in group A. A significant correlation between u-urea (mmol/L)/u-creatinine (mmol/L) and GFR was noted.
  
  
  CONCLUSIONS
  Hyperfiltration is sometimes present in children with cancer at diagnosis. This may be related to increased amino acid turn over in patients with a large tumor burden. An elevated initial GFR in a child with cancer, which normalizes after chemotherapy may indicate chemotherapy-induced decreased renal function, but can be due to normalization of an initially high GFR.
authors.affiliation: Division of Oncology-Haematology, Childhood Cancer Research Unit, Lund University, Skåne University Hospital, Lund, Sweden. lars.hjorth@med.lu.se
authors.forename: Lars
authors.initials: L
authors.lastname: Hjorth
authors.forename: Thomas
authors.initials: T
authors.lastname: Wiebe
authors.forename: Diana
authors.initials: D
authors.lastname: Karpman
mesh_terms: D000293:Adolescent; D000367:Age Factors; D001853:Bone Marrow / Q000473:pathology; D002648:Child; D002675:Child, Preschool; D003287:Contrast Media / Q000493:pharmacokinetics; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007223:Infant; D007472:Iohexol / Q000493:pharmacokinetics; D007668:Kidney / Q000378:metabolism*; D008297:Male; D009369:Neoplasms / Q000175:diagnosis* / Q000378:metabolism; D011379:Prognosis; D011446:Prospective Studies; D012737:Sex Factors
chemical_list: D003287:Contrast Media; D007472:Iohexol